The present invention relates to a seal member for a cylinder of a pneumatic tool and the seal member is a flexible collar mounted to the cylinder. The seal device has flanges engaged with ribs on an outside of the cylinder so that the seal member is securely mounted to the cylinder.
A conventional driving device for a pneumatic tool is shown in FIG. 1 and generally includes a head 10 connected to a base 15, a cylinder 13 is located between the head 10 and the base 15, and a rotary piston 14 rotatably received in the cylinder 13. The head 10 has an inlet tube 11 and an outlet tube 12 respectively extending outward from the head 10. A plurality of blades 141 extend radially outward from the rotary piston 14 and are engaged with an inside of the cylinder 13. An inlet hole 131 and an outlet hole 132 are respectively defined through the cylinder 13 so that the rotary piston 14 can rotate in the piston 13 by air entering into the piston via the inlet hole 131 and releasing from the cylinder 13 via the outlet hole 132. The efficiency of the cylinder 13 is affected by sealing between the cylinder 13 and the inside of the head 10. Unfortunately, the conventional sealing device is a seal ring mounted to the cylinder 13. The sealing ring only roughly seals a periphery of the cylinder 13 and this is not enough. However, the cylinder 13 usually shifted by vibration of the tool so that the positions of the inlet hole 131 and the outlet hole 132 are shifted and thereby resulting leakage.
The present invention intends to provide a seal member that is made of flexible material and securely mounted to the cylinder so as to establish a good sealing feature for the cylinder.
In accordance with one aspect of the present invention, there is provided a combination of a seal member and a cylinder for a pneumatic tool and comprising a ring-shaped cylinder in which a rotary piston is rotatably engaged. An inlet and an outlet are radially defined through the cylinder. Two first ribs respectively extend radially outward from the cylinder, and the first inlet is located between the two first ribs. Two second ribs respectively extend radially outward from the cylinder and the outlet inlet is located between the two second ribs. A seal member is mounted to the cylinder and has first hole and a second hole defined therethrough. A first flange extends radially outward from the seal member and the first hole is enclosed by the first flange. A second flange extends radially outward from the seal member and the second hole is enclosed by the second flange. The first inlet communicates with the first hole and the second inlet communicates with the second hole. The first ribs are engaged with and enclosed by the first flange, and the second ribs are engaged with and enclosed by the second flange.
The object of the present invention is to provide a seal member securely mounted to the ring-shaped cylinder by engaging flanges on the seal member with the ribs extending from the cylinder.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.